When a severe enough arc flash occurs the overcurrent protective device fuse or circuit breaker upstream of the fault interrupts the current.
Arc flash circuit breaker.
An arc fault circuit interrupter or afci breaker prevents fires by sensing when an electrical arc is about to occur and instantly disconnecting the damaged circuit before the arc builds enough heat to catch fire.
Enclosed circuit breaker with arc flash reduction maintenance system arms this document highlights the features and benefits of enclosed circuit breakers with the flash reduction maintenance system pdf 147 kb 5 30 2019 switching devices catalog.
Afcis are designed to sense an arc which is an electrical leak caused when a hot wire touches a neutral or ground but doesn t trigger the circuit breaker.
Afci protection is provided by either an afci circuit breaker installed at the electrical panel or by a receptacle specifically identified as providing arc fault protection.
Although current sensing circuitry enables afcis to detect arcing conditions unintended trickles of current may also cause the breaker to shut off afcis are very sensitive.
The term arc flash is used to describe low impedance connections in an electrical system which allows movement of unwanted electric discharge through the air from one voltage phase to another or to ground.
An arc fault circuit interrupter afci also known as an arc fault detection device afdd is a circuit breaker that breaks the circuit when it detects an electric arc in the circuit it protects to prevent electrical fires.
The engineers who have designed these afci breakers found that motors like the ones found in the power drill vacuums and treadmills produce a rhythmic mechanical arc pattern.